Troy Ounce to Grams — Gold and Silver Weight Conversion
- A troy ounce equals 31.1035 grams — heavier than a regular ounce (28.35 g). This matters for gold, silver, and all precious metal pricing.
Table of Contents
A troy ounce equals 31.1035 grams. This is the standard unit for gold, silver, platinum, and other precious metals worldwide. It is heavier than the everyday ounce (28.35 g) used for food and packages.
Confusing the two costs money. A gold price quoted in troy ounces does not convert the same way as kitchen measurements. Here is exactly how the numbers work.
Troy Ounce vs Regular Ounce
| Unit | Grams | Used For |
|---|---|---|
| Troy ounce (troy oz) | 31.1035 g | Gold, silver, precious metals |
| Avoirdupois ounce (oz) | 28.3495 g | Food, packages, everyday weight |
The difference is about 2.75 grams per ounce — nearly 10% heavier. At gold prices above $2,000 per troy oz, that gap represents over $170 per ounce of difference if you mix up the units.
Converting Troy Ounces to Grams
Multiply troy ounces by 31.1035 to get grams. Common precious metal weights:
| Troy Oz | Grams | Common Form |
|---|---|---|
| 0.1 troy oz | 3.11 g | small gold coin |
| 0.5 troy oz | 15.55 g | half-oz gold bar |
| 1 troy oz | 31.10 g | standard gold/silver coin |
| 10 troy oz | 311.0 g | ten-oz silver bar |
| 100 troy oz | 3,110 g | large silver bar |
| 400 troy oz | 12,441 g | standard gold bar (Good Delivery) |
Using the Unit Converter for Gold Weight
The unit converter on this page uses regular (avoirdupois) ounces, which equal 28.35 grams. For troy ounce conversions, multiply your troy oz amount by 31.1035 directly, or use the gram result and convert onward.
If you need to convert grams of gold to troy ounces: divide grams by 31.1035. For example, a 10-gram gold bar equals 0.3215 troy ounces.
Why Precious Metals Use Troy Ounces
The troy system dates to medieval Troyes, France — a major trading center where gold and silver weights were standardized. The troy system was adopted by the English mint in the 1400s and remains the global standard for precious metals to this day.
Troy pounds also exist (12 troy ounces per troy pound) but are rarely used. Precious metals are almost always quoted in troy ounces or grams.
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Open Unit Converter FreeFrequently Asked Questions
How many grams in a troy ounce?
1 troy ounce equals exactly 31.1034768 grams. For practical purposes, 31.10 grams is accurate enough.
Is the gold price per troy ounce or regular ounce?
Gold, silver, platinum, and palladium prices are always quoted in troy ounces — never regular ounces. Spot price per troy oz times 31.1035 gives the price per gram.
How do I convert grams of gold to troy ounces?
Divide grams by 31.1035. Example: 10 grams divided by 31.1035 = 0.3215 troy ounces.
What is 1 gram of gold worth?
Divide the current gold spot price (quoted in troy oz) by 31.1035 to get the price per gram. This changes with the market — check a live metals quote site for today's rate.
